O-loweralkyl-s-(2-oxopropyl-1) phosphonodithioates

ABSTRACT

Phosphonated mercaptals and mercaptoles corresponding to the formula   WHEREIN &#39;&#39;&#39;&#39;ALKYLENE&#39;&#39;&#39;&#39; MEANS A DIVALENT SATURATED ALIPHATIC RADICAL HAVING FROM ONE TO THREE CARBON ATOMS; R is selected from the group consisting of lower alkyl and phenyl and R&#39;&#39; is lower alkyl; X is selected from the group consisting of sulfur and oxygen; R2 is lower alkyl of from one to three carbon atoms.

United States Patent 1 Walsh [54] O-LOWERALKYL-S-(Z-OXOPROPYL-l)PHOSPHONODITHIOATES [75] Inventor: Edward Nelson Walsh, Chicago Heights,111.

[73] Assignee: Stauffer Chemical Company, New

York, NY.

[22] Filed: Sept. 28, 1970 21 Appl. No.; 76,301

Related U.S. Application Data [62] Division of Ser. No. 381,509, July 9,1964, Pat. No.

52 U.S. Cl ..260/946 [51] Int. Cl. ..C07f 9/16 [58] v Field of Search..260/946 [56] References Cited UNITED STATES PATENTS 2,976,309 3/1961Schrader ..260/946 X [111 3,725,512 1 Apr. 3, 1973 Primary ExaminerLewisGotts Assistant Examiner-Anton H. Sutto Anomey-Wayne C. Jaeschne et al.

57 ABSTRACT Phosphonated mercaptals and mercaptoles corresponding to theformula 0 lS-alkylene-l1't R'O/ wherein alkylene means a divalentsaturated aliphatic radical having from one to three carbon atoms; Risselected from the group consisting of lower alkyl and phenyl and R islower alkyl; X is selected from the group consisting of sulfur andoxygen; R is lower alkyl of from one to three carbon atoms.

4 Claims, No Drawings 1 O-LOWERALKYL-S-(2-OXOPROPYL-l)PHOSPHONODITHIOATES This application is a division ofcopendingapplication Ser. No. 381,509, filed July 9, 1964 now US. Pat.No. 3,564,013.

The present invention is concerned with a novel group of phosphonatedcyclic mercaptals, their method of preparation, and use as pesticides.Also the invention is concerned with the novel intermediates from whichthese pesticides are manufactured and a method of preparing the same.

The novel pesticides may be represented by the general formula laliphatic radical having from one to three carbon atoms; R and R areselected from the group consisting of lower alkyl and phenyl; the groupsrepresented by X are independently selected from the group consisting ofsulfur and oxygen; R is an alkyl from one to three carbons or hydrogenand n is an integer of from 1 to 2, inelusive. The lower alkyl radicalswhich are suitable for R and R are the straight and branched chainaliphatic radicals having from one to eight carbon atoms and include forexample, methyl, ethyl, propyl, isopropyl, amyl, octyl, and theIike.'The lower alkyl radicals which are suitable for R are the straightand branched chain aliphatic radicals having from one to three carbonatoms and include for example, methyl, ethyl,propyl, and isopropyl.

The general process for preparing the novel pesticides of the inventionmay be illustrated by the following reaction: 1

wherein R, R, R, X, n, and alkylene are the same as defined above. Thereaction is preferably carried out in the presence of a strong acidcatalyst such as boron trifluoride etherate or gaseous HCl; an inertorganic solvent such as ethyl ether, benzene, and the like may beused,but is not required. Reaction temperatures during these exothermicreactions are generally maintained between C. and 100C., and a preferredtemperature range is between 20C. and 50C. Higher temperatures may causeappreciable side products to form an inert organic solvent such asbenzene, ether,and the like, and then washed. The washing may beaccomplished with water or aqueous solutions of sodium bicarbonate,sodium sulfate, etc. (to remove the unreacted aldehyde or ketone).Normally the reaction will yield between 71 and 97 percent of thetheoretical predicatedamount of phosphonated cyclic mercaptal.

. The following examples illustrate specific pesticides of. theinvention andtheir, method of preparation,but shouldnot be construed aslimiting the broader aspects of the invention.

. EXAMPLEI 011i; SW-ICE:-

c ino s orn To 6.0 grams of (C,H,)(C,H,O)P(S)-S- CH C(0)(CH3) containedin a reactor flask fitted with a stirrer and thermometer was added 2.5grams of ethandithiol. The reactants were dissolved in 5 mi. of ethylether and 0.5. ml. of boron trifluoride etherate was added to catalyzethe're'action. A mild exothermic reaction ensued; the temperature washeld at 30C. to 35C. After stirring for 16 hours, 100 ml. of ethyl etherwas added, and the reactants were washed with 100 cc. of water. The.reactants'were counterwashed with 50 cc. of ethyl ether and 50 cc. ofwater; then filtered and concentrated to 60C. under 1 mm. Hg. Theconcentrated product consisted of 7.0 grams (87 percent yield) of2-methyl-2-(0-ethyl ethylphosphonodithiomethylene) l,3-dithiolane havingan index of refraction N 1.5458 and analysis of 11.7% P and 33.9% S ascompared to 10.2 P and 42.4% S, theoretical.

The following compounds were prepared by a procedure substantially inaccordance with Example 1.

EXAMPLE 2 /OCII2 -SCIIzC-CH: (111150 2 Sic":

Z-methyI-Z-(O-ethyl ethylphosphonodithiomethylene)- l,3-oxathio,laue;having .an index of refraction N,,r"== 1.5520, and analysis of10.8% Pand"33.5% S as coman analysis of 9. l% P and 31.5% S as compared to 8.9%P and 36.5% S, theoretical.

EXAMPLE 4 S-Ullz Crll o 2-methyl-2-(0-ethylmethylphosphonodithiomethylene)-1,3-dithiolane; having an index ofrefraction N 1.5899, and an analysis of 10.4% P and 41.0% S as comparedto 10.7% P and 44.4% S, theoretical.

EXAMPLE (1111 0 S-CIIQ 2-methyl-2-(0-ethylmethylphosphonodithiomethylene)-1,3-oxathiolane; having an index ofrefraction N 1.5571, and an analysis of 1 1.3% P and 33.4% S as comparedto 11.4% P and 35.0% S, theoretical.

The novel phosphonated aldehyde or ketone inter mediates useful in thepreparation of the novel pesticides of the invention may be representedby the general formula wherein alkylene, R, R, R and X are the same asdefined hereinbefore for the novel pesticides.

The general process for preparing the novel intermediates of theinvention may be illustrated by the following reaction:

cent of the theoretical predicted amount of phosphonated intermediate.

EXAMPLE6 To 21.2 grams of sodium nd 700 ml. ethanol contained in areactor flask fitted with a thermometer and stirring rod, while thetemperature was maintained between 25C. and 30C., was added hydrogensulfide until the solution was acidic to phenolphthalein. Whilemaintaining the temperature of the reactants at 25C., 50.0 grams ofethyl phosphonodichloridothionate was American cockroach added dropwiseover a period of 25 minutes. After stirring for an additional 30 minutesat 25C., the mixture was heated to 50C. and stirred for 30 minuteslonger. Then, 28.0 grams of chloroacetone was added dropwise over aperiod of six minutes while maintaining the temperature of the mixturebetween 20C. and 25C. The mixture was stirred for 30 minutes at 25C. andthen stirred at reflux for one hour. After cooling and filtering, themixture was concentrated to 60C. under 1 mm. Hg. The concentratedproduct consisted of 51.7 grams percent yield) ofO-ethyl-S-(Z-oxopropyl-l ethylphosphonodithioate having an index ofrefraction N 1.5309 and analysis of 12.7% P and 28.6% S

compared to 13.7% P and 28.3% S, theoretical.

The following specific compounds were prepared by a proceduresubstantially in accordance with that of Example 1:

EXAMPLE 7 0-ethyl-S(2-oxo-propyl-1 )-phenylphosphonodithioate having anindex of refraction N 1.5865, and analysis of 11.7% P and 23.9% S ascompared to 11.3% P and 23.3% S, theoretical.

EXAMPLE 8 0-ethy1-S-(2-oxo-propyl-1 )-methylphosphonodithioate having anindex of refraction N 1.5360, and analysis of 14.1% P and 30.1% S ascompared to 14.6% P and 30.2% S, theoretical.

Although the new phosphonated cyclic mercaptals have been found to begenerally active as pesticides, their miticidal activity, especiallywith the two-spotted mite, Tetranychus telarius, is unexpectedly high.Insecticidal activity for the phosphonated cyclic mercaptals isillustrated in Table I wherein the percentage kill among the pestspecies is reported for a specified quantity of candidate compound,expressed in micrograms g-herein termed the bioassay test), or for apercentage concentration in aqueous dispersion (hereinafter termed thescreening test). A slanted line is used to separate the percentage killfor the pest species shown on the left from the percentage concentration(screen ing) or total quantity (bioassay) shown on the right.

Insect Pest Species Housefly Musca domestica (Linn.)

Periplanela americana (Linn) Blatella germam'ca (Linn) Oncopeltu:fasciatu: (Dallas) German cockroach Spotted milkweed bug Mite TestSpecies Two-spotted mite Terranychu: telan'us (Linn) 6 TABLEI..\IORTALITY OF REPRESENTATIVE SPECIES OF cosmos: INSECT ORDERS ANDMI'TES T. (elan'us Compound (example number, M. domrs- I. mnrr- B. g(rm- O. em l i ir Systemic. sec supr tica icrum rmicn fnscinlur omcNymphs I Eggs ppm. 1, 50/0.1 v 50 01 50/001 50/001.v 50 3 2, a 50 30 500. 03 50 0. 01 50 0. 01 50/0.0l 50 0. 03 50 .s5 4, m. 50/25 50/0. 0550/005 50 003 50 0. 005 50/0. 01 50 001 50 1 5, pg..." 50/10 50 00350/01 50 0. 03 50/0. 005 50 0. 005 50 003 50 1 In the screening testsfor the insect species of Table I, used commercially in the form ofaqueous solutions from to 25 insects were caged in cardboard mailingwhen appreciably soluble, non-aqueous solutions, tubes 3% inches indiameter and zetinehes tall. The wettable powders, vap rs. and dusts asest suited to cages were supplied with cellophane bot d the conditionsof use. in many applications, fillers will screen tops. Food and waterwere supplied to each is be Q e P e the toxic f p For more cage.Dispersions of the test compounds were prepared spq app se mateflal m yW be e by dissolving one-half gram of the toxic materialin l0 Pure,undiluted ml. of acetone. This solution was then diluted with i usedhere"! the term pe e intended! the water containing 0.0l75% v/v Sponto221, an emulsifyresincted sense generally reeogmzed fi as ing agent, theamount of water being sufficient to dilute plying tefhe lower forms ofllfe customa rlly controlled the active ingredients to a concentrationof 0.1 percent by chem'cal means and excludmg the f m or below. The testinsects were then sprayed with this the vertebiatesi for example rodentsblrdst and large? dispersion. After 24 and 72 hours, counts were made toforms which are more controlled determine Mug and dead insectsmechanical means such as traps. it will be apparent to Some of thecompounds which showed high mortali- 25 one that tone t! 2 ty on houseflies in the screening test were bioassayed (JP-ate l f e on Y m testspecies i on domestica. In this test, a known quantity the tale ofactivity with species and orders not specifically toxicant was placed ina confined area. The same cages 8 $1 f d f l f shouldbe understoodtherefrom, as modificationswill 1 ml. of acetone. After the solvent wasevaporated by z iz g f to those skmd m the air-drying, a cage containinggroups of 25 female flies, L A co'mpound having the formula: three tofive days old, was placed over the residue. Counts of living and deadinsects were made 48 hours w after initiation of the test. O

it has been further found that the compounds of the ll ll presentinvention are excellent systemic miticides. In testing for systemicaction, pinto bean plants were placed in bottles containing 200 ml. ofthe test solution 40 v and were held in place with cotton plugs. Onlythe roots wherein ualkylenen means a divalent saturated were immersed-The Solutions were P' p y i aliphatic radical having from one to threecarbon solving the candle-me miti-cids in acetone or other atoms;R isselected from the group consistingof lower. suitable solvent and thendiluting with tap water. The alkyl and phenyl and is lower alkyl; x isselected final acetone concentration of the solu-tion was never f o hgroup consisting of m and oxygen; 2 is allowed to exceed 1 Peleent andxi' am 3 i lower alkyl of from one to three carbon atoms. tially testedat a concentration of 100 ppm. As soon as 2. O-ethyl-S-(Z-oxopropyl-lthe plants were placed in the solution, theywereincthylphosphonodithioate fested with mites. Mortalities of postembryonic, 3. O-ethyl-S-(Z-oxopropyl-l )-phennymph and ovicidal formswere determined seven days ylphosphonodithioate. after, initiation ofthe test. 4. O-ethyl-S-(Z-uxopropyl-l Although the above tests wereaccomplished with methylphosphonodithioate. aqueous dispersions, thetoxic compounds can alsobe it e a 5 5

2. 0-ethyl-S-(2-oxopropyl-1)-ethylphosphonodithioate. 3.0-ethyl-S-(2-oxopropyl-1)-phenylphosphonodithioate. 4.0-ethyl-S-(2-oxopropyl-1)-methylphosphonodithioate.